1. Field of the Invention
The present invention relates to an electronic combination still and movie camera with which it is possible to take both still and motion pictures purely electronically.
2. Description of the Prior Art
Recently an electronic camera has been proposed which is capable of taking a purely electronic still picture of an object and recording it by the combined use of an optoelectro transducer of a solid state image sensor or pickup tube and a recording device, such as a magnetic tape recorder. This type of electronic camera is attracting attention as a future substitute for the existing optical camera which requires a chemical treatment of the film.
In the case of taking a still picture, high picture quality is generally required. Thus, an optoelectro transducer with a large number of picture elements is needed and the number of quantize bits per picture element must be large. Since the frame speed is as low as 3 to 5 frames per second at maximum, even in the case of continuous photographing, the read rate of the optoelectro transducer may be low and, after all, the quantity of information required to record per unit time is small. Accordingly, the recording device therefor may be, for instance, a magnetic recording device of audio grade, by which the camera can be made small and inexpensive, and it is considered that such a camera would be a good match for the conventional optical camera.
By the way, it would be very convenient if still and motion pictures could be taken by one camera, which is difficult with the existing camera but can be accomplished relatively easily with a purely electronic camera because its arrangement is equivalent to a movie camera. In the case of taking a motion picture, however, the frame speed is high, for example, in the case of television, the frame speed is as high as 30 frames per second, and the quantity of information stored per unit time is larger than in the case of still photography; therefore, it is considered to be difficult to take motion pictures using an electronic camera with such a magnetic recording device of audio grade as mentioned above. For taking both still and motion pictures by one camera, it is necessary to employ a high-speed magnetic recording system of high accuracy sufficient to effect video-speed recording, accordingly, the camera is bulky and expensive.